Aortic diameter, wall stiffness, and wave reflection in systolic hypertension
Aortic diameter, wall stiffness, and wave reflection in systolic hypertension
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DOI：
10.1161/hypertensionaha.107.099721
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发表时间：
2008-01-01
期刊：
影响因子：
8.3
通讯作者：
Pfeffer, Marc A.
中科院分区：
文献类型：
--
作者：
Mitchell, Gary F.;Conlin, Paul R.;Pfeffer, Marc A.
收缩期高血压与脉压（PP）增加和心血管不良结局风险增加相关。然而，PP增加的发病机制仍然存在争议。一种假设认为，弹性蛋白断裂导致主动脉扩张、壁硬化和脉搏波速度增加，导致过早反射压力波，导致PP升高。另一种假设表明，近端主动脉僵硬度增加和主动脉直径减小导致压力和流量不匹配，导致前向压力波增加和PP增加。为了评估这两个假设，我们测量了脉动血流动力学和近端主动脉直径直接使用眼压计，超声成像，多普勒在167个收缩期高血压患者。研究前至少1周停用抗高血压药物。PP高于中位数的患者（75 mm Hg）的主动脉直径较低（2.94 +/- 0.36 vs 3.13 +/- 0.28 cm，P < 0.001）和更高的主动脉壁硬度（弹性-壁刚度乘积：16.1 +/- 0.7 vs. 15.7 +/- 0.7 ln[dyne/cm]，P < 0.001），增强指数无差异（19.9 +/- 10.4 vs. 17.5 +/-10.0%，P = 0.12）。主动脉内径和壁硬度均随年龄增长而增加（P < 0.001）。然而，在校正了年龄、性别、身高和体重，然后进一步校正了主动脉壁硬度、增强指数和平均动脉压的模型中，PP和主动脉直径之间的负相关性仍然显著（P < 0.001）。在收缩期高血压患者中，PP增加主要归因于室壁硬度增加和主动脉直径减小，而不是过早波反射。
Systolic hypertension is associated with increased pulse pressure ( PP) and increased risk for adverse cardiovascular outcomes. However the pathogenesis of increased PP remains controversial. One hypothesis suggests that aortic dilatation, wall stiffening and increased pulse wave velocity result from elastin fragmentation, leading to a premature reflected pressure wave that contributes to elevated PP. An alternative hypothesis suggests that increased proximal aortic stiffness and reduced aortic diameter leads to mismatch between pressure and flow, giving rise to an increased forward pressure wave and increased PP. To evaluate these two hypotheses, we measured pulsatile hemodynamics and proximal aortic diameter directly using tonometry, ultrasound imaging, and Doppler in 167 individuals with systolic hypertension. Antihypertensive medications were withdrawn for at least 1 week before study. Patients with PP above the median (75 mm Hg) had lower aortic diameter (2.94 +/- 0.36 versus 3.13 +/- 0.28 cm, P < 0.001) and higher aortic wall stiffness (elastance-wall stiffness product: 16.1 +/- 0.7 versus 15.7 +/- 0.7 ln[dyne/cm], P < 0.001) with no difference in augmentation index (19.9 +/- 10.4 versus 17.5 +/- 10.0%, P = 0.12). Aortic diameter and wall stiffness both increased with advancing age (P < 0.001). However, an inverse relation between PP and aortic diameter remained significant (P < 0.001) in models that adjusted for age, sex, height, and weight and then further adjusted for aortic wall stiffness, augmentation index, and mean arterial pressure. Among individuals with systolic hypertension, increased PP is primarily attributable to increased wall stiffness and reduced aortic diameter rather than premature wave reflection.